Attempts to prevent equine post neurectomy neuroma formation through retrograde transport of two neurotoxins, doxorubicin and ricin   总被引：2，自引：0，他引：2  

J F Cummings  S L Fubini  R J Todhunter 《Equine veterinary journal》1988,20(6):451-456

Digital neurectomies, performed to relieve pain and lameness, are often complicated postoperatively by formation of painful neuromas. In this study attempts were made to deliver lethal doses of neurotoxin to the cell bodies of the transected digital nerve fibres via long-distance retrograde axon transport and, thereby, prevent the regenerative changes that lead to neuroma formation. After applying doxorubicin in various ways to the digital nerve stumps of ponies, degenerating or necrotic neurones appeared only sporadically in the spinal ganglia. Although doxorubicin was largely ineffective in retrograde destruction of cell bodies, when absorbed in pledgets on the stumps it exerted a sustained action which prevented Schwann cell proliferation and axon sprouting. Ricin, in contrast to doxorubicin, was effective in retrograde destruction of sensory neurons. Many affected neurons were devoid of polysomes but packed with mitochondria; others had advanced to various stages in cytolysis. Despite its effectiveness, ricin cannot be recommended because of its extreme toxicity. The clinical use of retrograde transport in equine neurectomy will probably depend on future development of hybrid toxins with high neural specificity and low systemic toxicity.  相似文献   

Retrospective evaluation of repeat celiotomy in 53 horses with acute gastrointestinal disease     

J E Parker  S L Fubini  R J Todhunter 《Veterinary surgery : VS》1989,18(6):424-431

Fifty-three of 648 horses (8.2%) treated surgically for acute gastrointestinal obstruction were subjected to repeat celiotomy. Forty horses (75%) recovered from anesthesia after repeat celiotomy, and 26 horses (49%) were discharged from the clinic. Excluding two horses lost to follow-up, 10 of 51 horses (20%) survived long term. Horses subjected to repeat celiotomy had a significantly lower long-term survival rate than horses subjected to a single celiotomy. Twenty-eight horses had mechanical obstructions, and 22 had functional obstructions at the second surgery. Significantly more horses with mechanical obstructions recovered from anesthesia, but there was no difference in short-term or long-term survival. Seventy-seven percent of horses were subjected to two celiotomies without being discharged from the clinic between procedures. The intervals between primary and repeat celiotomies ranged from less than 24 hours to 4 years, with 89% of them being less than 2 months. Horses with functional obstructions at the second surgery had a significantly shorter interval between surgeries than horses with mechanical obstructions. Twenty-three horses had sequelae of the primary celiotomy, 19 had progression of their original disease, 8 had recurrence of the same condition, and 3 had unrelated problems. Intestinal ischemic necrosis was the most common diagnosis at repeat celiotomy, and small intestinal obstruction by adhesions was the second most frequent.  相似文献   

Progressive ataxia associated with degenerative thoracic myelopathy in Merino sheep     

PAW HARPER †  JW PLANT  KH WALKER  KG TIMMINS† 《Australian veterinary journal》1991,68(11):357-358

A neurological disorder in Merino sheep, characterised clinically by progressive posterior ataxia and microscopically by Wallerian degeneration in thoracic segments of the spinal cord, is described. Animals of both sexes were affected, with the earliest onset of disease being at 5 months of age. Most affected animals died before 2 years of age. The clinical, pathological and epidemiological features suggest that this degenerative thoracic myelopathy is a previously unrecognised entity differing from other reported causes of ataxia in sheep in Australia.  相似文献   

Surgical repair of urethral transection in a horse     

R J Todhunter  J E Parker 《Journal of the American Veterinary Medical Association》1988,193(9):1085-1086

A recently castrated horse was examined because of preputial and ventral abdominal swelling, prolapse of the preputial fold, and serosanguinous fluid dripping from the external urethral orifice. After a poor response to initial medical management, a urethral laceration was found during exploratory surgery. Half of the ventral portion of the corpus cavernosum penis had been transected. Primary closure was followed by healing without complications.  相似文献   

Quantitative ultrastructural anatomy of esophagus in different regions in the horse: effects of alternate methods of tissue processing     

R F Slocombe  R J Todhunter  J A Stick 《American journal of veterinary research》1982,43(7):1137-1142

A qualitative and quantitative study was made of 2 adult horses to determine the effect of specimen preparation and the influence of anatomically separate regions on the microscopic structure of the esophagus. The effects of 3 fixative solutions (formalin, Bouin's fixative and Karnovsky's fixative) and 4 histologic staining procedures (hematoxylin and eosin, Gomori's trichrome, Laidlow's reticulum, and orcein-elastin) were compared. Density-dependent image analysis was used to compare the relative contributions of elastic and reticular fibers in esophageal connective tissue for each region. Cross-sectional dimensions of the tissue layers which comprise the esophageal wall were obtained by light microscopic measurement and were compared for each region. The mucosal surface structure was examined by scanning electron microscopy. Our results indicate that specimen preparation has significant effects on the structural integrity of esophageal tissues. Bouin's fixative was inferior to the other fixatives in this regard. Furthermore, there are extensive regional differences in esophageal microstructure. Formalin-fixed tissues stained with either hematoxylin and eosin or Gomori's trichrome appear the most suitable for routine quantitative morphologic studies of the equine esophagus.  相似文献   

Effect of colostrum ingestion on indices of neutrophil phagocytosis and metabolism in newborn calves.     

P S Lombardo  D A Todhunter  R W Scholz  R J Eberhart 《American journal of veterinary research》1979,40(3):362-368

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Precision and Accuracy of Ground Reaction Force Normalization in a Heterogeneous Population of Dogs     

Ursula Krotscheck DVM  Diplomate ACVS  Rory J. Todhunter BVSc  Diplomate ACVS  Samantha A. Nelson DVM  Nathaniel B. Sutter PhD  Hussni O. Mohammed PhD 《Veterinary surgery : VS》2014,43(4):437-445

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Effect of Ulnar Ostectomy on Intra‐Articular Pressure Mapping and Contact Mechanics of the Congruent and Incongruent Canine Elbow Ex Vivo     

Ursula Krotscheck DVM  Diplomate ACVS  Sarah Kalafut DVM  Gregory Meloni BS  M.Eng  Margret S. Thompson DVM  Diplomate ACVR  Rory J. Todhunter BVSc  PhD  Diplomate ACVS  Hussni O. Mohammed PhD  Marjolein C.H. van der Meulen PhD 《Veterinary surgery : VS》2014,43(3):339-346

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Assessment of bone mineral density of the femoral head in dogs with early osteoarthritis     

Chalmers HJ  Dykes NL  Lust G  Farese JP  Burton-Wurster NI  Williams AJ  Todhunter RJ 《American journal of veterinary research》2006,67(5):796-800

OBJECTIVE: To compare the bone mineral density (BMD) of the proximal portion of the femur in dogs with and without early osteoarthritis secondary to hip dysplasia. ANIMALS: 24 dogs (3 Greyhounds, 6 Labrador-Greyhound crossbreeds, and 15 Labrador Retrievers). PROCEDURE: Computed tomography (CT) of the pelvis, including a bone-density phantom, was performed for each dog. Centrally located transverse CT slices and a computer workstation were used to identify 16 regions of interest (ROIs) in the proximal portion of the femur. For each ROI, the mean Hounsfield unit value was recorded; by use of the bone-density phantom and linear regression analysis, those values were converted to equivalent BMD (eBMD). Mean eBMD values for the subchondral and nonsubchondral ROIs in dogs with and without osteoarthritis (determined at necropsy) were compared. A mixed-model ANOVA and post hoc linear contrasts were used to evaluate the effects of osteoarthritis, breed, and sex on the BMD value. RESULTS: At necropsy, osteoarthritis was detected in 14 hip joints in 9 dogs; all lesions included early cartilage fibrillation. After adjusting for breed and sex, eBMD in subchondral ROIs 8 and 12 (adjacent to the fovea) were 8% and 6% higher, respectively, in osteoarthritis-affected dogs, compared with unaffected dogs; in the nonsubchondral ROIs, eBMD was 10% higher in osteoarthritis-affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with findings in unaffected dogs, increased eBMD in hip joints of dogs with early osteoarthritis supports a strong relationship between the subchondral and epiphyseal regions and articular cartilage in the pathogenesis and progression of osteoarthritis.  相似文献   

Desmotomy for treatment of chronic desmitis of the accessory ligament of the deep digital flexor tendon in a horse.          下载免费PDF全文

P G Todhunter  J Schumacher    S T Finn-Bodner 《The Canadian veterinary journal. La revue veterinaire canadienne》1997,38(10):637-639

Chronic lameness was determined to be caused by desmitis of the accessory ligament of the deep digital flexor tendon and adhesions associated with these 2 structures. Desmotomy of the accessory ligament, resection of adhesions, and controlled exercise during convalescence resulted in return to normal use without apparent lameness.  相似文献